This one is pretty tricky, and it all depends on where you live.
In the United States, both Original and Tropical Smarties are gluten-free. They note on their website to look for a specific UPC number on their packaging which verifies it safe to eat for people on a gluten-free diet. Note that Smarties Gummies have gluten-free ingredients, but they are produced in a facility where wheat is present so therefore they are not gluten-free.
Outside of the United States, Smarties are a different type of candy (similar to M&M’s). These products do contain gluten, so this means any Smarties outside of the US are not gluten-free. Please read the ingredient and nutrition label carefully. Need help in understanding what to look for on those labels? We have a guide - check it out!